From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <413AAF49.5070600@yahoo.com.au> Date: Sun, 05 Sep 2004 16:16:41 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [RFC][PATCH 0/3] beat kswapd with the proverbial clue-bat References: <413AA7B2.4000907@yahoo.com.au> <20040904230210.03fe3c11.davem@davemloft.net> In-Reply-To: <20040904230210.03fe3c11.davem@davemloft.net> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: "David S. Miller" Cc: akpm@osdl.org, torvalds@osdl.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: David S. Miller wrote: > On Sun, 05 Sep 2004 15:44:18 +1000 > Nick Piggin wrote: > > >>So my solution? Just teach kswapd and the watermark code about higher >>order allocations in a fairly simple way. If pages_low is (say), 1024KB, >>we now also require 512KB of order-1 and above pages, 256K of order-2 >>and up, 128K of order 3, etc. (perhaps we should stop at about order-3?) > > > Whether to stop at order 3 is indeed an interesting question. > > The reality is that the high-order allocations come mostly from folks > using jumbo 9K MTUs on gigabit and faster technologies. On x86, an > order 2 would cover those packet allocations, but on sparc64 for example > order 1 would be enough, whereas on a 2K PAGE_SIZE system order 3 would > be necessary. > Yeah I see. > People using e1000 cards are hitting this case, and some of the e1000 > developers are going to play around with using page array based SKBs > (via the existing SKB page frags mechanism). So instead of allocating > a huge linear chunk for RX packets, they'll allocate a header area of > 256 bytes then an array of pages to cover the rest. > Yes, I guess that would be ideal from the memory manager's POV. > Right now, my current suggestion would not be to stop at a certain order. > OK I'll keep it as is and we'll see how that goes. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org